The Impact of Disclosing Personalized Depression Risk Information on High-risk Individuals' Outcomes

Rationale: The proposed study stems from a CIHR project and is driven by the results of knowledge translation (KT) activities. The investigators developed the first sex-specific risk prediction models for major depressive episode (MDE) using data from over 10,000 Canadians. The models include age, personal and family history of MDE, childhood trauma, and predictors that may change over time. Using the models, individuals can answer the question: what is my risk of having a MDE in the next 4 years? Knowing this personalized risk information may assist health professionals in communicating with patients and planning preventive actions; disclosing the information may also empower consumers to actively engage in self-help. In the past 5 years, the KT activities with over 500 stakeholders informed that the investigators need to clearly delineate the benefits (enhanced risk perceptions and self-help) and potential risk (increased psychological distress and impaired function) of disclosing the information before implementing the tools.

The goal of this study is to produce evidence about the benefits and potential risks associated with risk disclosure (i.e., the expected outputs). The primary objectives are to compare those who do and do not receive personalized depression risk information in (1) accuracy of risk perceptions, the use of self-help strategies, and (2) changes in psychological distress and functional measures over one year among those who are at high risk of MDE. The secondary objective is to examine the differential impacts of the disclosure on the outcomes by demographics and levels of baseline risk. To achieve these objectives, the investigators propose a 3-year randomized controlled trial (RCT) with an embedded qualitative component.

The proposed study will be a RCT with an embedded qualitative component. The RCT will have one interventional arm (receiving personalized depression risk information) and one control arm. The personalized depression risk will be generated using the sex-specific prediction algorithms for MDE that we developed in Canadians aged 18+ years old. Because the prediction algorithms are sex-specific, the investigators propose to recruit 350 men and 350 women at baseline. After baseline assessment for eligibility, participants will be randomized into intervention and control groups, in men and women separately. To obtain in-depth information about how the personalized depression risk information is processed by participants and how the information affects them emotionally, the research team will conduct qualitative interviews 1 month after the personalized risk information is disclosed. To understand how the personalized risk information affect participants' health behaviors, the investigators will conduct another round of qualitative interviews at 12-month.

Recruitment: The target population of future preventive studies are high risk individuals in the general population, who reside in different regions across the country. For the proposed study, a feasible approach for recruiting eligible participants is the random digit dialing method (RDD). In the past 10 years, we have used the RDD for recruitment in CIHR-funded longitudinal studies and an ongoing national RCT funded by the Movember Foundation. Recruitment, screening and baseline assessment will be done by a telephone interview firm identified through a competitive bidding process.

A random sample of land line and cell phone numbers will be selected. When a household is reached, the person who is 18+ years will be assessed for eligibility. If a household has 2+ persons aged 18+ years, one will be randomly selected. The interviewers will explain the study objectives and procedures and answer questions. Potential participants will be ensured about confidentiality, that participation is voluntary and that they may withdraw at any time. Oral consent will be obtained before assessment of eligibility. Outcome measures will be assessed at baseline, 6 and 12-month.